AirNow Fire and Smoke Map Explained — Live Wildfire AQI + Smoke Plumes

AirNow Fire and Smoke Map Explained — Live Wildfire AQI + Smoke PlumesHow to read AirNow's Fire and Smoke Map — live PM2.5 sensors, NIFC active wildfire pins, NESDIS HMS satellite-detected smoke plumes. Cooling-center activation, outdoor-event calls, sensor cross-checks, and how it relates to the HRRR-Smoke forecast model.The Charts tab links to AirNow's Fire and Smoke Map — the official EPA + NOAA + USFS consumer view of wildfire impacts on air quality. It blends three layers: real-time PM2.5 from regulatory + community sensors, NIFC active wildfire pins, and NESDIS HMS satellite-derived smoke plumes drawn over the top.The three layers

Colored circles: Air quality (AQI) at PM2.5 sensor locations. Same EPA color scale as the dashboard's AQI panel — green is good, red+ is unhealthy. Sensors include both regulatory monitors and consumer (PurpleAir) stations.

Fire icons (flame): Active wildfires from the National Interagency Fire Center (NIFC). Click for size, name, containment percentage.

Gray smoke shading: NESDIS HMS satellite-detected smoke plumes — actual smoke seen from space in the past 24 hours. Light gray = thin / aloft, dark gray = thick / lower.

Why this view (and not just "HRRR-Smoke")HRRR-Smoke is the model that *forecasts* smoke 18-48 hours out. AirNow Fire and Smoke shows what's *happening right now*, derived from sensors and satellite. For most spotter / EMA decisions ("should we activate the cooling center? is the air bad enough to cancel football?") the live observation is what you want.NOAA's GSL is also deprecating the old HRRR-Smoke web page in favor of a new viewer (DESI), and the AirNow page is more stable for everyday use. If you want the explicit forecast model rather than observations, DESI has the HRRR-Smoke layer once you navigate to it.How to use it operationally

Cooling-center / shelter activation: Use the colored AQI circles in your county. Red or worse → activation common; purple/maroon → mandatory in most jurisdictions.

Outdoor event calls: Sports, school recess, outdoor work. Pair the AQI circles with the gray smoke overlay — if there's smoke aloft headed your way, AQI may worsen during the event.

Trans-regional smoke awareness: Canadian wildfires affecting the upper Midwest, California fires reaching Colorado — the HMS satellite layer makes the long-range transport visible at a glance.

Sensor cross-checks: If a single sensor reads wildly different from neighbors, it's often a localized issue (a backyard burn pile, a sensor next to an A/C exhaust). Trust the cluster average.

Spotter situational awareness: Smoke aloft attenuates radar (reduces echo strength) and makes visible-channel satellite less useful. The HMS smoke layer warns you when this is in play.

Caveats

Sensor coverage gaps: Rural areas may have no sensors within 50 miles. Use the satellite smoke layer as a fallback.

Consumer sensors run high: PurpleAir-style stations report higher PM2.5 than EPA monitors during heavy smoke. AirNow applies a correction but the calibration isn't perfect.

HMS is observed, not forecast: If you need to know "what's smoke going to be like tomorrow," check DESI or the HRRR-Smoke model directly.

Indoor air: Indoor concentrations with HVAC + MERV filters typically run 20–40% of outdoor on smoky days.

Source: fire.airnow.gov. Forecast model: sites.gsl.noaa.gov/desi (DESI / HRRR-Smoke).Part of the BloomWX learn library — beginner-friendly explainers covering every surface of the BloomWX weather dashboard. Open BloomWX to see live data for any U.S. county.